doc: fix wrong 4-byte length of pkt-line message
[git.git] / run-command.c
blobf5e1149f9b395e77c3d55a147332c1117746d7b1
1 #include "cache.h"
2 #include "run-command.h"
3 #include "exec-cmd.h"
4 #include "sigchain.h"
5 #include "argv-array.h"
6 #include "thread-utils.h"
7 #include "strbuf.h"
8 #include "string-list.h"
9 #include "quote.h"
11 void child_process_init(struct child_process *child)
13 memset(child, 0, sizeof(*child));
14 argv_array_init(&child->args);
15 argv_array_init(&child->env_array);
18 void child_process_clear(struct child_process *child)
20 argv_array_clear(&child->args);
21 argv_array_clear(&child->env_array);
24 struct child_to_clean {
25 pid_t pid;
26 struct child_process *process;
27 struct child_to_clean *next;
29 static struct child_to_clean *children_to_clean;
30 static int installed_child_cleanup_handler;
32 static void cleanup_children(int sig, int in_signal)
34 struct child_to_clean *children_to_wait_for = NULL;
36 while (children_to_clean) {
37 struct child_to_clean *p = children_to_clean;
38 children_to_clean = p->next;
40 if (p->process && !in_signal) {
41 struct child_process *process = p->process;
42 if (process->clean_on_exit_handler) {
43 trace_printf(
44 "trace: run_command: running exit handler for pid %"
45 PRIuMAX, (uintmax_t)p->pid
47 process->clean_on_exit_handler(process);
51 kill(p->pid, sig);
53 if (p->process && p->process->wait_after_clean) {
54 p->next = children_to_wait_for;
55 children_to_wait_for = p;
56 } else {
57 if (!in_signal)
58 free(p);
62 while (children_to_wait_for) {
63 struct child_to_clean *p = children_to_wait_for;
64 children_to_wait_for = p->next;
66 while (waitpid(p->pid, NULL, 0) < 0 && errno == EINTR)
67 ; /* spin waiting for process exit or error */
69 if (!in_signal)
70 free(p);
74 static void cleanup_children_on_signal(int sig)
76 cleanup_children(sig, 1);
77 sigchain_pop(sig);
78 raise(sig);
81 static void cleanup_children_on_exit(void)
83 cleanup_children(SIGTERM, 0);
86 static void mark_child_for_cleanup(pid_t pid, struct child_process *process)
88 struct child_to_clean *p = xmalloc(sizeof(*p));
89 p->pid = pid;
90 p->process = process;
91 p->next = children_to_clean;
92 children_to_clean = p;
94 if (!installed_child_cleanup_handler) {
95 atexit(cleanup_children_on_exit);
96 sigchain_push_common(cleanup_children_on_signal);
97 installed_child_cleanup_handler = 1;
101 static void clear_child_for_cleanup(pid_t pid)
103 struct child_to_clean **pp;
105 for (pp = &children_to_clean; *pp; pp = &(*pp)->next) {
106 struct child_to_clean *clean_me = *pp;
108 if (clean_me->pid == pid) {
109 *pp = clean_me->next;
110 free(clean_me);
111 return;
116 static inline void close_pair(int fd[2])
118 close(fd[0]);
119 close(fd[1]);
122 int is_executable(const char *name)
124 struct stat st;
126 if (stat(name, &st) || /* stat, not lstat */
127 !S_ISREG(st.st_mode))
128 return 0;
130 #if defined(GIT_WINDOWS_NATIVE)
132 * On Windows there is no executable bit. The file extension
133 * indicates whether it can be run as an executable, and Git
134 * has special-handling to detect scripts and launch them
135 * through the indicated script interpreter. We test for the
136 * file extension first because virus scanners may make
137 * it quite expensive to open many files.
139 if (ends_with(name, ".exe"))
140 return S_IXUSR;
144 * Now that we know it does not have an executable extension,
145 * peek into the file instead.
147 char buf[3] = { 0 };
148 int n;
149 int fd = open(name, O_RDONLY);
150 st.st_mode &= ~S_IXUSR;
151 if (fd >= 0) {
152 n = read(fd, buf, 2);
153 if (n == 2)
154 /* look for a she-bang */
155 if (!strcmp(buf, "#!"))
156 st.st_mode |= S_IXUSR;
157 close(fd);
160 #endif
161 return st.st_mode & S_IXUSR;
165 * Search $PATH for a command. This emulates the path search that
166 * execvp would perform, without actually executing the command so it
167 * can be used before fork() to prepare to run a command using
168 * execve() or after execvp() to diagnose why it failed.
170 * The caller should ensure that file contains no directory
171 * separators.
173 * Returns the path to the command, as found in $PATH or NULL if the
174 * command could not be found. The caller inherits ownership of the memory
175 * used to store the resultant path.
177 * This should not be used on Windows, where the $PATH search rules
178 * are more complicated (e.g., a search for "foo" should find
179 * "foo.exe").
181 static char *locate_in_PATH(const char *file)
183 const char *p = getenv("PATH");
184 struct strbuf buf = STRBUF_INIT;
186 if (!p || !*p)
187 return NULL;
189 while (1) {
190 const char *end = strchrnul(p, ':');
192 strbuf_reset(&buf);
194 /* POSIX specifies an empty entry as the current directory. */
195 if (end != p) {
196 strbuf_add(&buf, p, end - p);
197 strbuf_addch(&buf, '/');
199 strbuf_addstr(&buf, file);
201 if (is_executable(buf.buf))
202 return strbuf_detach(&buf, NULL);
204 if (!*end)
205 break;
206 p = end + 1;
209 strbuf_release(&buf);
210 return NULL;
213 static int exists_in_PATH(const char *file)
215 char *r = locate_in_PATH(file);
216 int found = r != NULL;
217 free(r);
218 return found;
221 int sane_execvp(const char *file, char * const argv[])
223 #ifndef GIT_WINDOWS_NATIVE
225 * execvp() doesn't return, so we all we can do is tell trace2
226 * what we are about to do and let it leave a hint in the log
227 * (unless of course the execvp() fails).
229 * we skip this for Windows because the compat layer already
230 * has to emulate the execvp() call anyway.
232 int exec_id = trace2_exec(file, (const char **)argv);
233 #endif
235 if (!execvp(file, argv))
236 return 0; /* cannot happen ;-) */
238 #ifndef GIT_WINDOWS_NATIVE
240 int ec = errno;
241 trace2_exec_result(exec_id, ec);
242 errno = ec;
244 #endif
247 * When a command can't be found because one of the directories
248 * listed in $PATH is unsearchable, execvp reports EACCES, but
249 * careful usability testing (read: analysis of occasional bug
250 * reports) reveals that "No such file or directory" is more
251 * intuitive.
253 * We avoid commands with "/", because execvp will not do $PATH
254 * lookups in that case.
256 * The reassignment of EACCES to errno looks like a no-op below,
257 * but we need to protect against exists_in_PATH overwriting errno.
259 if (errno == EACCES && !strchr(file, '/'))
260 errno = exists_in_PATH(file) ? EACCES : ENOENT;
261 else if (errno == ENOTDIR && !strchr(file, '/'))
262 errno = ENOENT;
263 return -1;
266 static const char **prepare_shell_cmd(struct argv_array *out, const char **argv)
268 if (!argv[0])
269 BUG("shell command is empty");
271 if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
272 #ifndef GIT_WINDOWS_NATIVE
273 argv_array_push(out, SHELL_PATH);
274 #else
275 argv_array_push(out, "sh");
276 #endif
277 argv_array_push(out, "-c");
280 * If we have no extra arguments, we do not even need to
281 * bother with the "$@" magic.
283 if (!argv[1])
284 argv_array_push(out, argv[0]);
285 else
286 argv_array_pushf(out, "%s \"$@\"", argv[0]);
289 argv_array_pushv(out, argv);
290 return out->argv;
293 #ifndef GIT_WINDOWS_NATIVE
294 static int child_notifier = -1;
296 enum child_errcode {
297 CHILD_ERR_CHDIR,
298 CHILD_ERR_DUP2,
299 CHILD_ERR_CLOSE,
300 CHILD_ERR_SIGPROCMASK,
301 CHILD_ERR_ENOENT,
302 CHILD_ERR_SILENT,
303 CHILD_ERR_ERRNO
306 struct child_err {
307 enum child_errcode err;
308 int syserr; /* errno */
311 static void child_die(enum child_errcode err)
313 struct child_err buf;
315 buf.err = err;
316 buf.syserr = errno;
318 /* write(2) on buf smaller than PIPE_BUF (min 512) is atomic: */
319 xwrite(child_notifier, &buf, sizeof(buf));
320 _exit(1);
323 static void child_dup2(int fd, int to)
325 if (dup2(fd, to) < 0)
326 child_die(CHILD_ERR_DUP2);
329 static void child_close(int fd)
331 if (close(fd))
332 child_die(CHILD_ERR_CLOSE);
335 static void child_close_pair(int fd[2])
337 child_close(fd[0]);
338 child_close(fd[1]);
342 * parent will make it look like the child spewed a fatal error and died
343 * this is needed to prevent changes to t0061.
345 static void fake_fatal(const char *err, va_list params)
347 vreportf("fatal: ", err, params);
350 static void child_error_fn(const char *err, va_list params)
352 const char msg[] = "error() should not be called in child\n";
353 xwrite(2, msg, sizeof(msg) - 1);
356 static void child_warn_fn(const char *err, va_list params)
358 const char msg[] = "warn() should not be called in child\n";
359 xwrite(2, msg, sizeof(msg) - 1);
362 static void NORETURN child_die_fn(const char *err, va_list params)
364 const char msg[] = "die() should not be called in child\n";
365 xwrite(2, msg, sizeof(msg) - 1);
366 _exit(2);
369 /* this runs in the parent process */
370 static void child_err_spew(struct child_process *cmd, struct child_err *cerr)
372 static void (*old_errfn)(const char *err, va_list params);
374 old_errfn = get_error_routine();
375 set_error_routine(fake_fatal);
376 errno = cerr->syserr;
378 switch (cerr->err) {
379 case CHILD_ERR_CHDIR:
380 error_errno("exec '%s': cd to '%s' failed",
381 cmd->argv[0], cmd->dir);
382 break;
383 case CHILD_ERR_DUP2:
384 error_errno("dup2() in child failed");
385 break;
386 case CHILD_ERR_CLOSE:
387 error_errno("close() in child failed");
388 break;
389 case CHILD_ERR_SIGPROCMASK:
390 error_errno("sigprocmask failed restoring signals");
391 break;
392 case CHILD_ERR_ENOENT:
393 error_errno("cannot run %s", cmd->argv[0]);
394 break;
395 case CHILD_ERR_SILENT:
396 break;
397 case CHILD_ERR_ERRNO:
398 error_errno("cannot exec '%s'", cmd->argv[0]);
399 break;
401 set_error_routine(old_errfn);
404 static int prepare_cmd(struct argv_array *out, const struct child_process *cmd)
406 if (!cmd->argv[0])
407 BUG("command is empty");
410 * Add SHELL_PATH so in the event exec fails with ENOEXEC we can
411 * attempt to interpret the command with 'sh'.
413 argv_array_push(out, SHELL_PATH);
415 if (cmd->git_cmd) {
416 prepare_git_cmd(out, cmd->argv);
417 } else if (cmd->use_shell) {
418 prepare_shell_cmd(out, cmd->argv);
419 } else {
420 argv_array_pushv(out, cmd->argv);
424 * If there are no '/' characters in the command then perform a path
425 * lookup and use the resolved path as the command to exec. If there
426 * are '/' characters, we have exec attempt to invoke the command
427 * directly.
429 if (!strchr(out->argv[1], '/')) {
430 char *program = locate_in_PATH(out->argv[1]);
431 if (program) {
432 free((char *)out->argv[1]);
433 out->argv[1] = program;
434 } else {
435 argv_array_clear(out);
436 errno = ENOENT;
437 return -1;
441 return 0;
444 static char **prep_childenv(const char *const *deltaenv)
446 extern char **environ;
447 char **childenv;
448 struct string_list env = STRING_LIST_INIT_DUP;
449 struct strbuf key = STRBUF_INIT;
450 const char *const *p;
451 int i;
453 /* Construct a sorted string list consisting of the current environ */
454 for (p = (const char *const *) environ; p && *p; p++) {
455 const char *equals = strchr(*p, '=');
457 if (equals) {
458 strbuf_reset(&key);
459 strbuf_add(&key, *p, equals - *p);
460 string_list_append(&env, key.buf)->util = (void *) *p;
461 } else {
462 string_list_append(&env, *p)->util = (void *) *p;
465 string_list_sort(&env);
467 /* Merge in 'deltaenv' with the current environ */
468 for (p = deltaenv; p && *p; p++) {
469 const char *equals = strchr(*p, '=');
471 if (equals) {
472 /* ('key=value'), insert or replace entry */
473 strbuf_reset(&key);
474 strbuf_add(&key, *p, equals - *p);
475 string_list_insert(&env, key.buf)->util = (void *) *p;
476 } else {
477 /* otherwise ('key') remove existing entry */
478 string_list_remove(&env, *p, 0);
482 /* Create an array of 'char *' to be used as the childenv */
483 ALLOC_ARRAY(childenv, env.nr + 1);
484 for (i = 0; i < env.nr; i++)
485 childenv[i] = env.items[i].util;
486 childenv[env.nr] = NULL;
488 string_list_clear(&env, 0);
489 strbuf_release(&key);
490 return childenv;
493 struct atfork_state {
494 #ifndef NO_PTHREADS
495 int cs;
496 #endif
497 sigset_t old;
500 #define CHECK_BUG(err, msg) \
501 do { \
502 int e = (err); \
503 if (e) \
504 BUG("%s: %s", msg, strerror(e)); \
505 } while(0)
507 static void atfork_prepare(struct atfork_state *as)
509 sigset_t all;
511 if (sigfillset(&all))
512 die_errno("sigfillset");
513 #ifdef NO_PTHREADS
514 if (sigprocmask(SIG_SETMASK, &all, &as->old))
515 die_errno("sigprocmask");
516 #else
517 CHECK_BUG(pthread_sigmask(SIG_SETMASK, &all, &as->old),
518 "blocking all signals");
519 CHECK_BUG(pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &as->cs),
520 "disabling cancellation");
521 #endif
524 static void atfork_parent(struct atfork_state *as)
526 #ifdef NO_PTHREADS
527 if (sigprocmask(SIG_SETMASK, &as->old, NULL))
528 die_errno("sigprocmask");
529 #else
530 CHECK_BUG(pthread_setcancelstate(as->cs, NULL),
531 "re-enabling cancellation");
532 CHECK_BUG(pthread_sigmask(SIG_SETMASK, &as->old, NULL),
533 "restoring signal mask");
534 #endif
536 #endif /* GIT_WINDOWS_NATIVE */
538 static inline void set_cloexec(int fd)
540 int flags = fcntl(fd, F_GETFD);
541 if (flags >= 0)
542 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
545 static int wait_or_whine(pid_t pid, const char *argv0, int in_signal)
547 int status, code = -1;
548 pid_t waiting;
549 int failed_errno = 0;
551 while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
552 ; /* nothing */
553 if (in_signal)
554 return 0;
556 if (waiting < 0) {
557 failed_errno = errno;
558 error_errno("waitpid for %s failed", argv0);
559 } else if (waiting != pid) {
560 error("waitpid is confused (%s)", argv0);
561 } else if (WIFSIGNALED(status)) {
562 code = WTERMSIG(status);
563 if (code != SIGINT && code != SIGQUIT && code != SIGPIPE)
564 error("%s died of signal %d", argv0, code);
566 * This return value is chosen so that code & 0xff
567 * mimics the exit code that a POSIX shell would report for
568 * a program that died from this signal.
570 code += 128;
571 } else if (WIFEXITED(status)) {
572 code = WEXITSTATUS(status);
573 } else {
574 error("waitpid is confused (%s)", argv0);
577 clear_child_for_cleanup(pid);
579 errno = failed_errno;
580 return code;
583 static void trace_add_env(struct strbuf *dst, const char *const *deltaenv)
585 struct string_list envs = STRING_LIST_INIT_DUP;
586 const char *const *e;
587 int i;
588 int printed_unset = 0;
590 /* Last one wins, see run-command.c:prep_childenv() for context */
591 for (e = deltaenv; e && *e; e++) {
592 struct strbuf key = STRBUF_INIT;
593 char *equals = strchr(*e, '=');
595 if (equals) {
596 strbuf_add(&key, *e, equals - *e);
597 string_list_insert(&envs, key.buf)->util = equals + 1;
598 } else {
599 string_list_insert(&envs, *e)->util = NULL;
601 strbuf_release(&key);
604 /* "unset X Y...;" */
605 for (i = 0; i < envs.nr; i++) {
606 const char *var = envs.items[i].string;
607 const char *val = envs.items[i].util;
609 if (val || !getenv(var))
610 continue;
612 if (!printed_unset) {
613 strbuf_addstr(dst, " unset");
614 printed_unset = 1;
616 strbuf_addf(dst, " %s", var);
618 if (printed_unset)
619 strbuf_addch(dst, ';');
621 /* ... followed by "A=B C=D ..." */
622 for (i = 0; i < envs.nr; i++) {
623 const char *var = envs.items[i].string;
624 const char *val = envs.items[i].util;
625 const char *oldval;
627 if (!val)
628 continue;
630 oldval = getenv(var);
631 if (oldval && !strcmp(val, oldval))
632 continue;
634 strbuf_addf(dst, " %s=", var);
635 sq_quote_buf_pretty(dst, val);
637 string_list_clear(&envs, 0);
640 static void trace_run_command(const struct child_process *cp)
642 struct strbuf buf = STRBUF_INIT;
644 if (!trace_want(&trace_default_key))
645 return;
647 strbuf_addstr(&buf, "trace: run_command:");
648 if (cp->dir) {
649 strbuf_addstr(&buf, " cd ");
650 sq_quote_buf_pretty(&buf, cp->dir);
651 strbuf_addch(&buf, ';');
654 * The caller is responsible for initializing cp->env from
655 * cp->env_array if needed. We only check one place.
657 if (cp->env)
658 trace_add_env(&buf, cp->env);
659 if (cp->git_cmd)
660 strbuf_addstr(&buf, " git");
661 sq_quote_argv_pretty(&buf, cp->argv);
663 trace_printf("%s", buf.buf);
664 strbuf_release(&buf);
667 int start_command(struct child_process *cmd)
669 int need_in, need_out, need_err;
670 int fdin[2], fdout[2], fderr[2];
671 int failed_errno;
672 char *str;
674 if (!cmd->argv)
675 cmd->argv = cmd->args.argv;
676 if (!cmd->env)
677 cmd->env = cmd->env_array.argv;
680 * In case of errors we must keep the promise to close FDs
681 * that have been passed in via ->in and ->out.
684 need_in = !cmd->no_stdin && cmd->in < 0;
685 if (need_in) {
686 if (pipe(fdin) < 0) {
687 failed_errno = errno;
688 if (cmd->out > 0)
689 close(cmd->out);
690 str = "standard input";
691 goto fail_pipe;
693 cmd->in = fdin[1];
696 need_out = !cmd->no_stdout
697 && !cmd->stdout_to_stderr
698 && cmd->out < 0;
699 if (need_out) {
700 if (pipe(fdout) < 0) {
701 failed_errno = errno;
702 if (need_in)
703 close_pair(fdin);
704 else if (cmd->in)
705 close(cmd->in);
706 str = "standard output";
707 goto fail_pipe;
709 cmd->out = fdout[0];
712 need_err = !cmd->no_stderr && cmd->err < 0;
713 if (need_err) {
714 if (pipe(fderr) < 0) {
715 failed_errno = errno;
716 if (need_in)
717 close_pair(fdin);
718 else if (cmd->in)
719 close(cmd->in);
720 if (need_out)
721 close_pair(fdout);
722 else if (cmd->out)
723 close(cmd->out);
724 str = "standard error";
725 fail_pipe:
726 error("cannot create %s pipe for %s: %s",
727 str, cmd->argv[0], strerror(failed_errno));
728 child_process_clear(cmd);
729 errno = failed_errno;
730 return -1;
732 cmd->err = fderr[0];
735 trace2_child_start(cmd);
736 trace_run_command(cmd);
738 fflush(NULL);
740 #ifndef GIT_WINDOWS_NATIVE
742 int notify_pipe[2];
743 int null_fd = -1;
744 char **childenv;
745 struct argv_array argv = ARGV_ARRAY_INIT;
746 struct child_err cerr;
747 struct atfork_state as;
749 if (prepare_cmd(&argv, cmd) < 0) {
750 failed_errno = errno;
751 cmd->pid = -1;
752 if (!cmd->silent_exec_failure)
753 error_errno("cannot run %s", cmd->argv[0]);
754 goto end_of_spawn;
757 if (pipe(notify_pipe))
758 notify_pipe[0] = notify_pipe[1] = -1;
760 if (cmd->no_stdin || cmd->no_stdout || cmd->no_stderr) {
761 null_fd = open("/dev/null", O_RDWR | O_CLOEXEC);
762 if (null_fd < 0)
763 die_errno(_("open /dev/null failed"));
764 set_cloexec(null_fd);
767 childenv = prep_childenv(cmd->env);
768 atfork_prepare(&as);
771 * NOTE: In order to prevent deadlocking when using threads special
772 * care should be taken with the function calls made in between the
773 * fork() and exec() calls. No calls should be made to functions which
774 * require acquiring a lock (e.g. malloc) as the lock could have been
775 * held by another thread at the time of forking, causing the lock to
776 * never be released in the child process. This means only
777 * Async-Signal-Safe functions are permitted in the child.
779 cmd->pid = fork();
780 failed_errno = errno;
781 if (!cmd->pid) {
782 int sig;
784 * Ensure the default die/error/warn routines do not get
785 * called, they can take stdio locks and malloc.
787 set_die_routine(child_die_fn);
788 set_error_routine(child_error_fn);
789 set_warn_routine(child_warn_fn);
791 close(notify_pipe[0]);
792 set_cloexec(notify_pipe[1]);
793 child_notifier = notify_pipe[1];
795 if (cmd->no_stdin)
796 child_dup2(null_fd, 0);
797 else if (need_in) {
798 child_dup2(fdin[0], 0);
799 child_close_pair(fdin);
800 } else if (cmd->in) {
801 child_dup2(cmd->in, 0);
802 child_close(cmd->in);
805 if (cmd->no_stderr)
806 child_dup2(null_fd, 2);
807 else if (need_err) {
808 child_dup2(fderr[1], 2);
809 child_close_pair(fderr);
810 } else if (cmd->err > 1) {
811 child_dup2(cmd->err, 2);
812 child_close(cmd->err);
815 if (cmd->no_stdout)
816 child_dup2(null_fd, 1);
817 else if (cmd->stdout_to_stderr)
818 child_dup2(2, 1);
819 else if (need_out) {
820 child_dup2(fdout[1], 1);
821 child_close_pair(fdout);
822 } else if (cmd->out > 1) {
823 child_dup2(cmd->out, 1);
824 child_close(cmd->out);
827 if (cmd->dir && chdir(cmd->dir))
828 child_die(CHILD_ERR_CHDIR);
831 * restore default signal handlers here, in case
832 * we catch a signal right before execve below
834 for (sig = 1; sig < NSIG; sig++) {
835 /* ignored signals get reset to SIG_DFL on execve */
836 if (signal(sig, SIG_DFL) == SIG_IGN)
837 signal(sig, SIG_IGN);
840 if (sigprocmask(SIG_SETMASK, &as.old, NULL) != 0)
841 child_die(CHILD_ERR_SIGPROCMASK);
844 * Attempt to exec using the command and arguments starting at
845 * argv.argv[1]. argv.argv[0] contains SHELL_PATH which will
846 * be used in the event exec failed with ENOEXEC at which point
847 * we will try to interpret the command using 'sh'.
849 execve(argv.argv[1], (char *const *) argv.argv + 1,
850 (char *const *) childenv);
851 if (errno == ENOEXEC)
852 execve(argv.argv[0], (char *const *) argv.argv,
853 (char *const *) childenv);
855 if (errno == ENOENT) {
856 if (cmd->silent_exec_failure)
857 child_die(CHILD_ERR_SILENT);
858 child_die(CHILD_ERR_ENOENT);
859 } else {
860 child_die(CHILD_ERR_ERRNO);
863 atfork_parent(&as);
864 if (cmd->pid < 0)
865 error_errno("cannot fork() for %s", cmd->argv[0]);
866 else if (cmd->clean_on_exit)
867 mark_child_for_cleanup(cmd->pid, cmd);
870 * Wait for child's exec. If the exec succeeds (or if fork()
871 * failed), EOF is seen immediately by the parent. Otherwise, the
872 * child process sends a child_err struct.
873 * Note that use of this infrastructure is completely advisory,
874 * therefore, we keep error checks minimal.
876 close(notify_pipe[1]);
877 if (xread(notify_pipe[0], &cerr, sizeof(cerr)) == sizeof(cerr)) {
879 * At this point we know that fork() succeeded, but exec()
880 * failed. Errors have been reported to our stderr.
882 wait_or_whine(cmd->pid, cmd->argv[0], 0);
883 child_err_spew(cmd, &cerr);
884 failed_errno = errno;
885 cmd->pid = -1;
887 close(notify_pipe[0]);
889 if (null_fd >= 0)
890 close(null_fd);
891 argv_array_clear(&argv);
892 free(childenv);
894 end_of_spawn:
896 #else
898 int fhin = 0, fhout = 1, fherr = 2;
899 const char **sargv = cmd->argv;
900 struct argv_array nargv = ARGV_ARRAY_INIT;
902 if (cmd->no_stdin)
903 fhin = open("/dev/null", O_RDWR);
904 else if (need_in)
905 fhin = dup(fdin[0]);
906 else if (cmd->in)
907 fhin = dup(cmd->in);
909 if (cmd->no_stderr)
910 fherr = open("/dev/null", O_RDWR);
911 else if (need_err)
912 fherr = dup(fderr[1]);
913 else if (cmd->err > 2)
914 fherr = dup(cmd->err);
916 if (cmd->no_stdout)
917 fhout = open("/dev/null", O_RDWR);
918 else if (cmd->stdout_to_stderr)
919 fhout = dup(fherr);
920 else if (need_out)
921 fhout = dup(fdout[1]);
922 else if (cmd->out > 1)
923 fhout = dup(cmd->out);
925 if (cmd->git_cmd)
926 cmd->argv = prepare_git_cmd(&nargv, cmd->argv);
927 else if (cmd->use_shell)
928 cmd->argv = prepare_shell_cmd(&nargv, cmd->argv);
930 cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, (char**) cmd->env,
931 cmd->dir, fhin, fhout, fherr);
932 failed_errno = errno;
933 if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
934 error_errno("cannot spawn %s", cmd->argv[0]);
935 if (cmd->clean_on_exit && cmd->pid >= 0)
936 mark_child_for_cleanup(cmd->pid, cmd);
938 argv_array_clear(&nargv);
939 cmd->argv = sargv;
940 if (fhin != 0)
941 close(fhin);
942 if (fhout != 1)
943 close(fhout);
944 if (fherr != 2)
945 close(fherr);
947 #endif
949 if (cmd->pid < 0) {
950 trace2_child_exit(cmd, -1);
952 if (need_in)
953 close_pair(fdin);
954 else if (cmd->in)
955 close(cmd->in);
956 if (need_out)
957 close_pair(fdout);
958 else if (cmd->out)
959 close(cmd->out);
960 if (need_err)
961 close_pair(fderr);
962 else if (cmd->err)
963 close(cmd->err);
964 child_process_clear(cmd);
965 errno = failed_errno;
966 return -1;
969 if (need_in)
970 close(fdin[0]);
971 else if (cmd->in)
972 close(cmd->in);
974 if (need_out)
975 close(fdout[1]);
976 else if (cmd->out)
977 close(cmd->out);
979 if (need_err)
980 close(fderr[1]);
981 else if (cmd->err)
982 close(cmd->err);
984 return 0;
987 int finish_command(struct child_process *cmd)
989 int ret = wait_or_whine(cmd->pid, cmd->argv[0], 0);
990 trace2_child_exit(cmd, ret);
991 child_process_clear(cmd);
992 return ret;
995 int finish_command_in_signal(struct child_process *cmd)
997 int ret = wait_or_whine(cmd->pid, cmd->argv[0], 1);
998 trace2_child_exit(cmd, ret);
999 return ret;
1003 int run_command(struct child_process *cmd)
1005 int code;
1007 if (cmd->out < 0 || cmd->err < 0)
1008 BUG("run_command with a pipe can cause deadlock");
1010 code = start_command(cmd);
1011 if (code)
1012 return code;
1013 return finish_command(cmd);
1016 int run_command_v_opt(const char **argv, int opt)
1018 return run_command_v_opt_cd_env(argv, opt, NULL, NULL);
1021 int run_command_v_opt_tr2(const char **argv, int opt, const char *tr2_class)
1023 return run_command_v_opt_cd_env_tr2(argv, opt, NULL, NULL, tr2_class);
1026 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
1028 return run_command_v_opt_cd_env_tr2(argv, opt, dir, env, NULL);
1031 int run_command_v_opt_cd_env_tr2(const char **argv, int opt, const char *dir,
1032 const char *const *env, const char *tr2_class)
1034 struct child_process cmd = CHILD_PROCESS_INIT;
1035 cmd.argv = argv;
1036 cmd.no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
1037 cmd.git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
1038 cmd.stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
1039 cmd.silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
1040 cmd.use_shell = opt & RUN_USING_SHELL ? 1 : 0;
1041 cmd.clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0;
1042 cmd.dir = dir;
1043 cmd.env = env;
1044 cmd.trace2_child_class = tr2_class;
1045 return run_command(&cmd);
1048 #ifndef NO_PTHREADS
1049 static pthread_t main_thread;
1050 static int main_thread_set;
1051 static pthread_key_t async_key;
1052 static pthread_key_t async_die_counter;
1054 static void *run_thread(void *data)
1056 struct async *async = data;
1057 intptr_t ret;
1059 if (async->isolate_sigpipe) {
1060 sigset_t mask;
1061 sigemptyset(&mask);
1062 sigaddset(&mask, SIGPIPE);
1063 if (pthread_sigmask(SIG_BLOCK, &mask, NULL) < 0) {
1064 ret = error("unable to block SIGPIPE in async thread");
1065 return (void *)ret;
1069 pthread_setspecific(async_key, async);
1070 ret = async->proc(async->proc_in, async->proc_out, async->data);
1071 return (void *)ret;
1074 static NORETURN void die_async(const char *err, va_list params)
1076 vreportf("fatal: ", err, params);
1078 if (in_async()) {
1079 struct async *async = pthread_getspecific(async_key);
1080 if (async->proc_in >= 0)
1081 close(async->proc_in);
1082 if (async->proc_out >= 0)
1083 close(async->proc_out);
1084 pthread_exit((void *)128);
1087 exit(128);
1090 static int async_die_is_recursing(void)
1092 void *ret = pthread_getspecific(async_die_counter);
1093 pthread_setspecific(async_die_counter, (void *)1);
1094 return ret != NULL;
1097 int in_async(void)
1099 if (!main_thread_set)
1100 return 0; /* no asyncs started yet */
1101 return !pthread_equal(main_thread, pthread_self());
1104 static void NORETURN async_exit(int code)
1106 pthread_exit((void *)(intptr_t)code);
1109 #else
1111 static struct {
1112 void (**handlers)(void);
1113 size_t nr;
1114 size_t alloc;
1115 } git_atexit_hdlrs;
1117 static int git_atexit_installed;
1119 static void git_atexit_dispatch(void)
1121 size_t i;
1123 for (i=git_atexit_hdlrs.nr ; i ; i--)
1124 git_atexit_hdlrs.handlers[i-1]();
1127 static void git_atexit_clear(void)
1129 free(git_atexit_hdlrs.handlers);
1130 memset(&git_atexit_hdlrs, 0, sizeof(git_atexit_hdlrs));
1131 git_atexit_installed = 0;
1134 #undef atexit
1135 int git_atexit(void (*handler)(void))
1137 ALLOC_GROW(git_atexit_hdlrs.handlers, git_atexit_hdlrs.nr + 1, git_atexit_hdlrs.alloc);
1138 git_atexit_hdlrs.handlers[git_atexit_hdlrs.nr++] = handler;
1139 if (!git_atexit_installed) {
1140 if (atexit(&git_atexit_dispatch))
1141 return -1;
1142 git_atexit_installed = 1;
1144 return 0;
1146 #define atexit git_atexit
1148 static int process_is_async;
1149 int in_async(void)
1151 return process_is_async;
1154 static void NORETURN async_exit(int code)
1156 exit(code);
1159 #endif
1161 void check_pipe(int err)
1163 if (err == EPIPE) {
1164 if (in_async())
1165 async_exit(141);
1167 signal(SIGPIPE, SIG_DFL);
1168 raise(SIGPIPE);
1169 /* Should never happen, but just in case... */
1170 exit(141);
1174 int start_async(struct async *async)
1176 int need_in, need_out;
1177 int fdin[2], fdout[2];
1178 int proc_in, proc_out;
1180 need_in = async->in < 0;
1181 if (need_in) {
1182 if (pipe(fdin) < 0) {
1183 if (async->out > 0)
1184 close(async->out);
1185 return error_errno("cannot create pipe");
1187 async->in = fdin[1];
1190 need_out = async->out < 0;
1191 if (need_out) {
1192 if (pipe(fdout) < 0) {
1193 if (need_in)
1194 close_pair(fdin);
1195 else if (async->in)
1196 close(async->in);
1197 return error_errno("cannot create pipe");
1199 async->out = fdout[0];
1202 if (need_in)
1203 proc_in = fdin[0];
1204 else if (async->in)
1205 proc_in = async->in;
1206 else
1207 proc_in = -1;
1209 if (need_out)
1210 proc_out = fdout[1];
1211 else if (async->out)
1212 proc_out = async->out;
1213 else
1214 proc_out = -1;
1216 #ifdef NO_PTHREADS
1217 /* Flush stdio before fork() to avoid cloning buffers */
1218 fflush(NULL);
1220 async->pid = fork();
1221 if (async->pid < 0) {
1222 error_errno("fork (async) failed");
1223 goto error;
1225 if (!async->pid) {
1226 if (need_in)
1227 close(fdin[1]);
1228 if (need_out)
1229 close(fdout[0]);
1230 git_atexit_clear();
1231 process_is_async = 1;
1232 exit(!!async->proc(proc_in, proc_out, async->data));
1235 mark_child_for_cleanup(async->pid, NULL);
1237 if (need_in)
1238 close(fdin[0]);
1239 else if (async->in)
1240 close(async->in);
1242 if (need_out)
1243 close(fdout[1]);
1244 else if (async->out)
1245 close(async->out);
1246 #else
1247 if (!main_thread_set) {
1249 * We assume that the first time that start_async is called
1250 * it is from the main thread.
1252 main_thread_set = 1;
1253 main_thread = pthread_self();
1254 pthread_key_create(&async_key, NULL);
1255 pthread_key_create(&async_die_counter, NULL);
1256 set_die_routine(die_async);
1257 set_die_is_recursing_routine(async_die_is_recursing);
1260 if (proc_in >= 0)
1261 set_cloexec(proc_in);
1262 if (proc_out >= 0)
1263 set_cloexec(proc_out);
1264 async->proc_in = proc_in;
1265 async->proc_out = proc_out;
1267 int err = pthread_create(&async->tid, NULL, run_thread, async);
1268 if (err) {
1269 error(_("cannot create async thread: %s"), strerror(err));
1270 goto error;
1273 #endif
1274 return 0;
1276 error:
1277 if (need_in)
1278 close_pair(fdin);
1279 else if (async->in)
1280 close(async->in);
1282 if (need_out)
1283 close_pair(fdout);
1284 else if (async->out)
1285 close(async->out);
1286 return -1;
1289 int finish_async(struct async *async)
1291 #ifdef NO_PTHREADS
1292 return wait_or_whine(async->pid, "child process", 0);
1293 #else
1294 void *ret = (void *)(intptr_t)(-1);
1296 if (pthread_join(async->tid, &ret))
1297 error("pthread_join failed");
1298 return (int)(intptr_t)ret;
1299 #endif
1302 int async_with_fork(void)
1304 #ifdef NO_PTHREADS
1305 return 1;
1306 #else
1307 return 0;
1308 #endif
1311 const char *find_hook(const char *name)
1313 static struct strbuf path = STRBUF_INIT;
1315 strbuf_reset(&path);
1316 strbuf_git_path(&path, "hooks/%s", name);
1317 if (access(path.buf, X_OK) < 0) {
1318 int err = errno;
1320 #ifdef STRIP_EXTENSION
1321 strbuf_addstr(&path, STRIP_EXTENSION);
1322 if (access(path.buf, X_OK) >= 0)
1323 return path.buf;
1324 if (errno == EACCES)
1325 err = errno;
1326 #endif
1328 if (err == EACCES && advice_ignored_hook) {
1329 static struct string_list advise_given = STRING_LIST_INIT_DUP;
1331 if (!string_list_lookup(&advise_given, name)) {
1332 string_list_insert(&advise_given, name);
1333 advise(_("The '%s' hook was ignored because "
1334 "it's not set as executable.\n"
1335 "You can disable this warning with "
1336 "`git config advice.ignoredHook false`."),
1337 path.buf);
1340 return NULL;
1342 return path.buf;
1345 int run_hook_ve(const char *const *env, const char *name, va_list args)
1347 struct child_process hook = CHILD_PROCESS_INIT;
1348 const char *p;
1350 p = find_hook(name);
1351 if (!p)
1352 return 0;
1354 argv_array_push(&hook.args, p);
1355 while ((p = va_arg(args, const char *)))
1356 argv_array_push(&hook.args, p);
1357 hook.env = env;
1358 hook.no_stdin = 1;
1359 hook.stdout_to_stderr = 1;
1360 hook.trace2_hook_name = name;
1362 return run_command(&hook);
1365 int run_hook_le(const char *const *env, const char *name, ...)
1367 va_list args;
1368 int ret;
1370 va_start(args, name);
1371 ret = run_hook_ve(env, name, args);
1372 va_end(args);
1374 return ret;
1377 struct io_pump {
1378 /* initialized by caller */
1379 int fd;
1380 int type; /* POLLOUT or POLLIN */
1381 union {
1382 struct {
1383 const char *buf;
1384 size_t len;
1385 } out;
1386 struct {
1387 struct strbuf *buf;
1388 size_t hint;
1389 } in;
1390 } u;
1392 /* returned by pump_io */
1393 int error; /* 0 for success, otherwise errno */
1395 /* internal use */
1396 struct pollfd *pfd;
1399 static int pump_io_round(struct io_pump *slots, int nr, struct pollfd *pfd)
1401 int pollsize = 0;
1402 int i;
1404 for (i = 0; i < nr; i++) {
1405 struct io_pump *io = &slots[i];
1406 if (io->fd < 0)
1407 continue;
1408 pfd[pollsize].fd = io->fd;
1409 pfd[pollsize].events = io->type;
1410 io->pfd = &pfd[pollsize++];
1413 if (!pollsize)
1414 return 0;
1416 if (poll(pfd, pollsize, -1) < 0) {
1417 if (errno == EINTR)
1418 return 1;
1419 die_errno("poll failed");
1422 for (i = 0; i < nr; i++) {
1423 struct io_pump *io = &slots[i];
1425 if (io->fd < 0)
1426 continue;
1428 if (!(io->pfd->revents & (POLLOUT|POLLIN|POLLHUP|POLLERR|POLLNVAL)))
1429 continue;
1431 if (io->type == POLLOUT) {
1432 ssize_t len = xwrite(io->fd,
1433 io->u.out.buf, io->u.out.len);
1434 if (len < 0) {
1435 io->error = errno;
1436 close(io->fd);
1437 io->fd = -1;
1438 } else {
1439 io->u.out.buf += len;
1440 io->u.out.len -= len;
1441 if (!io->u.out.len) {
1442 close(io->fd);
1443 io->fd = -1;
1448 if (io->type == POLLIN) {
1449 ssize_t len = strbuf_read_once(io->u.in.buf,
1450 io->fd, io->u.in.hint);
1451 if (len < 0)
1452 io->error = errno;
1453 if (len <= 0) {
1454 close(io->fd);
1455 io->fd = -1;
1460 return 1;
1463 static int pump_io(struct io_pump *slots, int nr)
1465 struct pollfd *pfd;
1466 int i;
1468 for (i = 0; i < nr; i++)
1469 slots[i].error = 0;
1471 ALLOC_ARRAY(pfd, nr);
1472 while (pump_io_round(slots, nr, pfd))
1473 ; /* nothing */
1474 free(pfd);
1476 /* There may be multiple errno values, so just pick the first. */
1477 for (i = 0; i < nr; i++) {
1478 if (slots[i].error) {
1479 errno = slots[i].error;
1480 return -1;
1483 return 0;
1487 int pipe_command(struct child_process *cmd,
1488 const char *in, size_t in_len,
1489 struct strbuf *out, size_t out_hint,
1490 struct strbuf *err, size_t err_hint)
1492 struct io_pump io[3];
1493 int nr = 0;
1495 if (in)
1496 cmd->in = -1;
1497 if (out)
1498 cmd->out = -1;
1499 if (err)
1500 cmd->err = -1;
1502 if (start_command(cmd) < 0)
1503 return -1;
1505 if (in) {
1506 io[nr].fd = cmd->in;
1507 io[nr].type = POLLOUT;
1508 io[nr].u.out.buf = in;
1509 io[nr].u.out.len = in_len;
1510 nr++;
1512 if (out) {
1513 io[nr].fd = cmd->out;
1514 io[nr].type = POLLIN;
1515 io[nr].u.in.buf = out;
1516 io[nr].u.in.hint = out_hint;
1517 nr++;
1519 if (err) {
1520 io[nr].fd = cmd->err;
1521 io[nr].type = POLLIN;
1522 io[nr].u.in.buf = err;
1523 io[nr].u.in.hint = err_hint;
1524 nr++;
1527 if (pump_io(io, nr) < 0) {
1528 finish_command(cmd); /* throw away exit code */
1529 return -1;
1532 return finish_command(cmd);
1535 enum child_state {
1536 GIT_CP_FREE,
1537 GIT_CP_WORKING,
1538 GIT_CP_WAIT_CLEANUP,
1541 struct parallel_processes {
1542 void *data;
1544 int max_processes;
1545 int nr_processes;
1547 get_next_task_fn get_next_task;
1548 start_failure_fn start_failure;
1549 task_finished_fn task_finished;
1551 struct {
1552 enum child_state state;
1553 struct child_process process;
1554 struct strbuf err;
1555 void *data;
1556 } *children;
1558 * The struct pollfd is logically part of *children,
1559 * but the system call expects it as its own array.
1561 struct pollfd *pfd;
1563 unsigned shutdown : 1;
1565 int output_owner;
1566 struct strbuf buffered_output; /* of finished children */
1569 static int default_start_failure(struct strbuf *out,
1570 void *pp_cb,
1571 void *pp_task_cb)
1573 return 0;
1576 static int default_task_finished(int result,
1577 struct strbuf *out,
1578 void *pp_cb,
1579 void *pp_task_cb)
1581 return 0;
1584 static void kill_children(struct parallel_processes *pp, int signo)
1586 int i, n = pp->max_processes;
1588 for (i = 0; i < n; i++)
1589 if (pp->children[i].state == GIT_CP_WORKING)
1590 kill(pp->children[i].process.pid, signo);
1593 static struct parallel_processes *pp_for_signal;
1595 static void handle_children_on_signal(int signo)
1597 kill_children(pp_for_signal, signo);
1598 sigchain_pop(signo);
1599 raise(signo);
1602 static void pp_init(struct parallel_processes *pp,
1603 int n,
1604 get_next_task_fn get_next_task,
1605 start_failure_fn start_failure,
1606 task_finished_fn task_finished,
1607 void *data)
1609 int i;
1611 if (n < 1)
1612 n = online_cpus();
1614 pp->max_processes = n;
1616 trace_printf("run_processes_parallel: preparing to run up to %d tasks", n);
1618 pp->data = data;
1619 if (!get_next_task)
1620 BUG("you need to specify a get_next_task function");
1621 pp->get_next_task = get_next_task;
1623 pp->start_failure = start_failure ? start_failure : default_start_failure;
1624 pp->task_finished = task_finished ? task_finished : default_task_finished;
1626 pp->nr_processes = 0;
1627 pp->output_owner = 0;
1628 pp->shutdown = 0;
1629 pp->children = xcalloc(n, sizeof(*pp->children));
1630 pp->pfd = xcalloc(n, sizeof(*pp->pfd));
1631 strbuf_init(&pp->buffered_output, 0);
1633 for (i = 0; i < n; i++) {
1634 strbuf_init(&pp->children[i].err, 0);
1635 child_process_init(&pp->children[i].process);
1636 pp->pfd[i].events = POLLIN | POLLHUP;
1637 pp->pfd[i].fd = -1;
1640 pp_for_signal = pp;
1641 sigchain_push_common(handle_children_on_signal);
1644 static void pp_cleanup(struct parallel_processes *pp)
1646 int i;
1648 trace_printf("run_processes_parallel: done");
1649 for (i = 0; i < pp->max_processes; i++) {
1650 strbuf_release(&pp->children[i].err);
1651 child_process_clear(&pp->children[i].process);
1654 free(pp->children);
1655 free(pp->pfd);
1658 * When get_next_task added messages to the buffer in its last
1659 * iteration, the buffered output is non empty.
1661 strbuf_write(&pp->buffered_output, stderr);
1662 strbuf_release(&pp->buffered_output);
1664 sigchain_pop_common();
1667 /* returns
1668 * 0 if a new task was started.
1669 * 1 if no new jobs was started (get_next_task ran out of work, non critical
1670 * problem with starting a new command)
1671 * <0 no new job was started, user wishes to shutdown early. Use negative code
1672 * to signal the children.
1674 static int pp_start_one(struct parallel_processes *pp)
1676 int i, code;
1678 for (i = 0; i < pp->max_processes; i++)
1679 if (pp->children[i].state == GIT_CP_FREE)
1680 break;
1681 if (i == pp->max_processes)
1682 BUG("bookkeeping is hard");
1684 code = pp->get_next_task(&pp->children[i].process,
1685 &pp->children[i].err,
1686 pp->data,
1687 &pp->children[i].data);
1688 if (!code) {
1689 strbuf_addbuf(&pp->buffered_output, &pp->children[i].err);
1690 strbuf_reset(&pp->children[i].err);
1691 return 1;
1693 pp->children[i].process.err = -1;
1694 pp->children[i].process.stdout_to_stderr = 1;
1695 pp->children[i].process.no_stdin = 1;
1697 if (start_command(&pp->children[i].process)) {
1698 code = pp->start_failure(&pp->children[i].err,
1699 pp->data,
1700 pp->children[i].data);
1701 strbuf_addbuf(&pp->buffered_output, &pp->children[i].err);
1702 strbuf_reset(&pp->children[i].err);
1703 if (code)
1704 pp->shutdown = 1;
1705 return code;
1708 pp->nr_processes++;
1709 pp->children[i].state = GIT_CP_WORKING;
1710 pp->pfd[i].fd = pp->children[i].process.err;
1711 return 0;
1714 static void pp_buffer_stderr(struct parallel_processes *pp, int output_timeout)
1716 int i;
1718 while ((i = poll(pp->pfd, pp->max_processes, output_timeout)) < 0) {
1719 if (errno == EINTR)
1720 continue;
1721 pp_cleanup(pp);
1722 die_errno("poll");
1725 /* Buffer output from all pipes. */
1726 for (i = 0; i < pp->max_processes; i++) {
1727 if (pp->children[i].state == GIT_CP_WORKING &&
1728 pp->pfd[i].revents & (POLLIN | POLLHUP)) {
1729 int n = strbuf_read_once(&pp->children[i].err,
1730 pp->children[i].process.err, 0);
1731 if (n == 0) {
1732 close(pp->children[i].process.err);
1733 pp->children[i].state = GIT_CP_WAIT_CLEANUP;
1734 } else if (n < 0)
1735 if (errno != EAGAIN)
1736 die_errno("read");
1741 static void pp_output(struct parallel_processes *pp)
1743 int i = pp->output_owner;
1744 if (pp->children[i].state == GIT_CP_WORKING &&
1745 pp->children[i].err.len) {
1746 strbuf_write(&pp->children[i].err, stderr);
1747 strbuf_reset(&pp->children[i].err);
1751 static int pp_collect_finished(struct parallel_processes *pp)
1753 int i, code;
1754 int n = pp->max_processes;
1755 int result = 0;
1757 while (pp->nr_processes > 0) {
1758 for (i = 0; i < pp->max_processes; i++)
1759 if (pp->children[i].state == GIT_CP_WAIT_CLEANUP)
1760 break;
1761 if (i == pp->max_processes)
1762 break;
1764 code = finish_command(&pp->children[i].process);
1766 code = pp->task_finished(code,
1767 &pp->children[i].err, pp->data,
1768 pp->children[i].data);
1770 if (code)
1771 result = code;
1772 if (code < 0)
1773 break;
1775 pp->nr_processes--;
1776 pp->children[i].state = GIT_CP_FREE;
1777 pp->pfd[i].fd = -1;
1778 child_process_init(&pp->children[i].process);
1780 if (i != pp->output_owner) {
1781 strbuf_addbuf(&pp->buffered_output, &pp->children[i].err);
1782 strbuf_reset(&pp->children[i].err);
1783 } else {
1784 strbuf_write(&pp->children[i].err, stderr);
1785 strbuf_reset(&pp->children[i].err);
1787 /* Output all other finished child processes */
1788 strbuf_write(&pp->buffered_output, stderr);
1789 strbuf_reset(&pp->buffered_output);
1792 * Pick next process to output live.
1793 * NEEDSWORK:
1794 * For now we pick it randomly by doing a round
1795 * robin. Later we may want to pick the one with
1796 * the most output or the longest or shortest
1797 * running process time.
1799 for (i = 0; i < n; i++)
1800 if (pp->children[(pp->output_owner + i) % n].state == GIT_CP_WORKING)
1801 break;
1802 pp->output_owner = (pp->output_owner + i) % n;
1805 return result;
1808 int run_processes_parallel(int n,
1809 get_next_task_fn get_next_task,
1810 start_failure_fn start_failure,
1811 task_finished_fn task_finished,
1812 void *pp_cb)
1814 int i, code;
1815 int output_timeout = 100;
1816 int spawn_cap = 4;
1817 struct parallel_processes pp;
1819 pp_init(&pp, n, get_next_task, start_failure, task_finished, pp_cb);
1820 while (1) {
1821 for (i = 0;
1822 i < spawn_cap && !pp.shutdown &&
1823 pp.nr_processes < pp.max_processes;
1824 i++) {
1825 code = pp_start_one(&pp);
1826 if (!code)
1827 continue;
1828 if (code < 0) {
1829 pp.shutdown = 1;
1830 kill_children(&pp, -code);
1832 break;
1834 if (!pp.nr_processes)
1835 break;
1836 pp_buffer_stderr(&pp, output_timeout);
1837 pp_output(&pp);
1838 code = pp_collect_finished(&pp);
1839 if (code) {
1840 pp.shutdown = 1;
1841 if (code < 0)
1842 kill_children(&pp, -code);
1846 pp_cleanup(&pp);
1847 return 0;
1850 int run_processes_parallel_tr2(int n, get_next_task_fn get_next_task,
1851 start_failure_fn start_failure,
1852 task_finished_fn task_finished, void *pp_cb,
1853 const char *tr2_category, const char *tr2_label)
1855 int result;
1857 trace2_region_enter_printf(tr2_category, tr2_label, NULL, "max:%d",
1858 ((n < 1) ? online_cpus() : n));
1860 result = run_processes_parallel(n, get_next_task, start_failure,
1861 task_finished, pp_cb);
1863 trace2_region_leave(tr2_category, tr2_label, NULL);
1865 return result;